2004 Jetta BEW cranks, no start.

Mhracing23

Member
Joined
Jul 26, 2022
Location
Manitoba, Canada
TDI
2004 Jetta BEW
Good day everyone, desperate for some VW troublshooting knowledge. Car had been daily driven up until one morning it was slow to crank. Added a booster pack and turns over quickly but won't fire. I have noticed I don't get a glow plug light or check engine light when key power on. I have checked all the fuses under hood and behind drivers door. I have good 12v on edc fuse. Replaced 109 relay with no change. Pinned out the edc connecter and I have no power on hot pins, unless I remove 109 relay and jump it, then I have 12v but still no fire. Checked and cleaned the Edc ground below windshield with no change. Only code I am getting with scanner is P0864 TCM Communication Circuit Range / performance. Any tip or help would be greatly appreciated.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Sounds like the engine controller is not powering up.

I'd pull off the cowl cover and remove the ECU plugs and check for any corrosion, then check for power and ground at the big wires first, see what you find there.

I'd also get a suitable scan tool, and see if you can communicate with the CAN Gateway, and ask it if it is just the Engine controller that is off line, that may help narrow it down.
 

Mhracing23

Member
Joined
Jul 26, 2022
Location
Manitoba, Canada
TDI
2004 Jetta BEW
Sounds like the engine controller is not powering up.

I'd pull off the cowl cover and remove the ECU plugs and check for any corrosion, then check for power and ground at the big wires first, see what you find there.

I'd also get a suitable scan tool, and see if you can communicate with the CAN Gateway, and ask it if it is just the Engine controller that is off line, that may help narrow it down.
Cowl cover has been removed and EDC plugs inspected and no corrosion found. I only have power to EDC when I jumper the 109 relay, and even still no glow plug or check engine lights. Just finished cleaning all terminals on battery and power and grounds under and near battery tray. Still no change. Any suggestions on what scan tool to buy that won't break the bank? Thanks
 
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muzy

Veteran Member
Joined
Aug 19, 2012
Location
Southern Alberta
TDI
02 jetta TDI
Diagnostic is not my strong point. At least not when compared to some wizards on this form.
If your 109 is not activating, what else is not. And I think it receives signal from ignition.
Cheers
 

Mhracing23

Member
Joined
Jul 26, 2022
Location
Manitoba, Canada
TDI
2004 Jetta BEW
Diagnostic is not my strong point. At least not when compared to some wizards on this form.
If your 109 is not activating, what else is not. And I think it receives signal from ignition.
Cheers
With the relay installed it does activate somthing under the hood near the battery side of the engine... I can hear it when I turn the key on.. without the relay it is silent. Pretty sure I seen somewhere that the relay uses a grd that runs through the ecu so if that's bad then It could explain the power issue with relay installed. On a side note i noticed the radio has no power with key on but Fan and other controls work.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
This is why I suggested seeing if you could communicate with the CAN Gateway. But, if you don't want to get a good scan tool, the parts shotgun approach might [eventually] get you there. Or your bank account with be empty, one of the two.
 

Mhracing23

Member
Joined
Jul 26, 2022
Location
Manitoba, Canada
TDI
2004 Jetta BEW
This is why I suggested seeing if you could communicate with the CAN Gateway. But, if you don't want to get a good scan tool, the parts shotgun approach might [eventually] get you there. Or your bank account with be empty, one of the two.
I am not shotgunning parts, I have access to try a free ECU. Since all my trouble shooting has been pointing at a bad ECU I figured I would try a free component rather than jumping into a 300usd diagnostic tool right away.
 

jokila

Vendor
Joined
Dec 3, 2004
Location
Houston, Texas
TDI
2003 Jetta GLS, Manual
I am not shotgunning parts, I have access to try a free ECU. Since all my trouble shooting has been pointing at a bad ECU I figured I would try a free component rather than jumping into a 300usd diagnostic tool right away.
No one knows what your parts cost and if they weren't free it's an expensive way to troubleshoot. You understand the concept?
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
No Cel, GP light at initial key on is a problem. Start with the big wire/fuse on top of the battery (#4 maybe). Then check for voltage inside the car, fuse block maybe. Check all fuses. Next would be ignition, sometimes the wires or even the device get fluggerd. Our cars get a lot of wiring/connect issues as they age.
And please don't take offense, it is social media. Folks will mongle, but generally everyone does try to help.
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI, 2005 VW Passat wagon TDI X3, 2001 VW golf TDI, 1980 VW rabbit pickup,
Pay a little bit and get vcds and see if it'll communicate. It is likely not a fried ecm, just saying.
You can put another ecm in, but you'll need the skc and vcds to adapt it to work in your car, as the immobilizer will keep it from running without that.
If the glow plug and check engine light isn't coming on, it's showing that you're not getting power to the ecm and etc. The ignition switch is one possible cause of that, but also a blown fuse 34 or broken wire in the circuit from the ignition switch.
 

DivineChaos

Top Post Dawg
Joined
Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
It was intended to be funny and temper his approach to the advice he was already given, like from Oilhammer.
I get it. My point is still valid bud. More flies with honey. Some take offense to it. Same thing could have been said with better wording.
 

Mhracing23

Member
Joined
Jul 26, 2022
Location
Manitoba, Canada
TDI
2004 Jetta BEW
Good news!! The free ecu fixed it. Check engine light,glow plug, and fuel pump cycle with key on. And she fired right up... the anti theft isnt happy so it killed it right away but I am sure I can get that programmed locally.
 

DivineChaos

Top Post Dawg
Joined
Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
Good news!! The free ecu fixed it. Check engine light,glow plug, and fuel pump cycle with key on. And she fired right up... the anti theft isnt happy so it killed it right away but I am sure I can get that programmed locally.
You'd need your keys reprogrammed. Call a locksmith. I forget what year. But older ones can be programmed with vcds. they still have the key for that ecu?
 
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Mhracing23

Member
Joined
Jul 26, 2022
Location
Manitoba, Canada
TDI
2004 Jetta BEW
You'd need your keys reprogrammed. Call a locksmith. I forget what year. But older ones can be programmed with vcds. programmed.. they still have the key for that ecu?
No they don't have keys for that ecu. It was just a test unit I borrowed from a parted car. I have access to an ecu to purchase that is an exact numbers matching unit to mine. Does that mean it will be programmed the same as far as keys or every car is different no matter if ecu data numbers match exactly? Thanks
 
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